With the continuous development of communication technologies, the technology in which it is able to make the voice service switched from a Packet Switching (PS) domain to a Circuit Switching (CS) domain appears. This technology is called SRVCC switching technology. The mode of SRVCC switching includes switching from a Time Division-Synchronization Code Division Multiple Access (TD-SCDMA) system to a TD-SCDMA system, switching from a TD-SCDMA system to a Global System for Mobile Communications (GSM) system, switching from a Long Term Evolution (LTE) system to a TD-SCDMA system, and switching from an LTE system to a GSM system. In a multi-mode system, the application of the SRVCC switching technology can greatly improve user experience.
A process of SRVCC switching is briefly described by taking SRVCC switching from an LTE system to a TD-SCDMA system for an example.
If the current system of a terminal is the LTE system, then a PS domain voice service is initiated. After the PS domain voice service is established, during the process of a call, a network side decides, due to signal quality, to carry out SRVCC switching. After resources of the network side are switched, the network side informs the terminal to switch to the TD-SCDMA system from the current LTE system. After the switching is completed, the terminal can continue to carry out the voice service under the TD-SCDMA system. During the process, other PS domain voice services may also be switched to the TD-SCDMA system for proceeding.
Due to that a voice service under an original system may be subjected to encryption and integrity protection, in order to switch the voice service to a target system from the original system successfully, original authentication parameters need to be treated such that they are applicable to the target system. During the mapping, the following problems would be involved, for example, whether to convert authentication parameters, when to start the conversion of the authentication parameters, when to store the converted authentication parameters into a card, and how to proceed the authentication parameters when the SRVCC switching fails. However, no related technology capable of solving the above problems is disclosed at present.